It is quite easy to trigger ORA-904:
from emp e;
and so on. What column name did the message exhibited?
I see your point, but I took a working query from an application, gathered query results successfully (f9), went to explain plan (f10) and received the error.
Then I uncommented columns that had been excluded from the query, and the explain plan worked.
So I recreated the issue with emp (saw my comments go green), went to note error and could no longer recreate the issue.
This morning I think the issue may have been me toggling between database sessions.